WEAR OF ALUMINUM-ALLOY MATRIX COMPOSITES IN LUBRICATED CONFORMAL CONTACT WITH CASE-HARDENED STEEL

The wear behavior of SiC particle-reinforced aluminum alloy matrix com posites as journal bearing materials in conformal contact against case hardened AISI 1016 steel under mixed lubrication conditions using SAE 10W30 oil was investigated. The bearings exhibited weight gain, follo wed by weight loss and subsequent weight gain as the sliding distance increased. Iron transfer and tribochemical reaction product formation were responsible for the observed weight gain. The surfaces of the com posites contained transferred iron, layers rich in Fe, S, P and Zn, an d hard tribo-deposits of high phosphorus concentration. The hard tribo -deposits were thought to be an important factor in lubrication breakd own and contact failure.